1. Technical Field
This application relates to devices in which electrical signals control the flow of electrical power and, more particularly, to devices that control reactance through the application of a control current.
2. Related Art
Some saturable reactors control current flow through changing reluctance (magnetic resistance). The core of these reactors may be magnetically saturated in which the magnetic domains of the core are lined up with a magnetizing force.
Before reaching saturation, the reactor's magnetic permeability and impedance to a winding with an alternating current may be large, limiting alternating current flow. As the core reaches saturation, its reactance (impedance) may be significantly smaller. Once saturated, the core may simulate an air core.
In power applications, such as applications that may convey megawatts of power at kilovolts voltage levels to a load, significant amounts of biasing current and a very low resistance might be needed to bias a core into saturation. Superconductive windings and cryogenic equipment are required to lower the resistance and power consumption of a biasing circuit. And, a significant biasing source would also be required to drive the core into saturation.